[CIFS] Add posix (advisory) byte range locking support to cifs client

Samba (version 3) server support for this is also currently being
done.  This client code is in an experimental path (requires enabling
/proc/fs/cifs/Experimental) while it is being tested.

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index cf846c7..25d7df4 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -6,7 +6,9 @@
 read responses when buffer size over 64K and also fix wrap of
 max smb buffer size when CIFSMaxBufSize over 64K.  Fix oops in
 cifs_user_read and cifs_readpages (when EAGAIN on send of smb
-on socket is returned over and over)
+on socket is returned over and over).  Add POSIX (advisory) byte range
+locking support (requires server with newest CIFS UNIX Extensions
+to the protocol implemented).
 
 Version 1.40
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